This invention relates in general to antifriction bearings and more particularly to an antifriction bearing that produces electrical energy and its related assembly.
The brakes of freight cars used on North American railroads rely on compressed air for their operation. In the typical freight train, a compressor located in the locomotive supplies compressed air to the individual freight cars through a so-called "train line" that runs the length of the train and hence passes through every car. To apply the brakes, the engineer in locomotive operates a control which changes the pressure of the air in the train line. But the train line does not experience an instantaneous change in pressure. Instead, the change occurs progressively from car to car throughout the length of the train. As a consequence the brakes are applied successively from car to car, and this is not desirable.
The train line represents the only source of external energy available at the typical freight car. While electrically operated controls respond much more quickly and uniformly than air operated devices--or at least air operated brakes controlled from the locomotive--electrical control lines and circuits have not been a part of freight cars. Even if the cars had electrically operated devices for directing pressurized air from the train line to the brakes, the devices would necessarily require solenoids which draw considerable current, and the electrical devices for an entire freight train would require too much current to be serviced by an electrical cable of moderate size. Yet a need exists for brakes which respond more quickly and uniformly than those now available.
Currently, railroads have under consideration a braking system which will rely on electrical control devices on the individual rail cars for controlling the compressed air directed from the train line to the brakes of such cars. An electrically generated signal, perhaps transmitted as an electromagnetic wave, would activate all of the control devices instantaneously. This, of course, would apply the brakes of all the cars in a train simultaneously. But an electrically operated control device on a rail car requires a source of electrical energy at the car, and perhaps the most practical source is a battery. In short, each rail car having an electrically operated control device for activating its brakes should have a battery for supplying the electrical energy--and also a generator of some type for recharging the battery.
To be sure, the cabooses formerly used at the ends of freight trains carried batteries which supplied electricity for lighting and for radio communications with the locomotives at the other ends of such trains. Moreover, the typical caboose had an alternator or generator for recharging the batteries. But the alternator or generator required a complex system of pulleys and belts for coupling it with one of the axles, an arrangement which demanded time and effort to install and more to maintain.
The present invention resides in a bearing that enables an axle, such as on a rail car, to rotate freely while supporting a substantial load. The bearing further produces electrical energy when the axle rotates, and yet is as small as conventional bearings of similar load capacity. The assembly of which it is a part for the most part utilizes traditional components, and the bearing may be substituted for traditional bearings in standard side frames. The invention further resides in the bearing and its related components which together provide an improved bearing assembly. The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.